Water is one of the most vital resources for sustenance of life and the terrestrial ecosystem can’t function without it. Water is essential for everything people do as such drinking, irrigation, agricultural production, power generation, etc. Ground water is one of the most valuable natural resources which supports human health, economic development and ecological diversity. Its unique qualities that it is generally free from pathogens, easily accessible, has stable temperature and free from suspended particles have made it the most important and preferred sources of water for agricultural and domestic uses.
The quality of ground water plays an essential role and vital component of our life support system. It mainly depends upon both surface and subsurface geology. Natural function like rainfall and other climatic conditions also contribute towards the water quality.
Hydrogeology of an area is mainly controlled by the geology, geomorphology and rainfall of that area. The main source of groundwater is rainfall which precipitates on the earth surface and percolates downward through soil zone to form groundwater within open spaces of geological rock formation at different depth. The rate of infiltration of rainwater as well as storage potential of groundwater mainly depends on the geomorphic setup as well as the geological formation of any area. India is a developing country, facing many problems like population, industrial and agricultural growth. All these sections consume large volume of both surface and subsurface water. Stratigraphic, lithologic and geomorphic set up control both the water resources of the country. The annual rainfall also varies considerably from year to year. Ground water is the most important source of drinking water for about 70% of Indian population depend.
All these factors affect the potentiality of ground water from place to place. The recharging of ground water in the country is through annual precipitation, rivers and ocean. Saline incursion in the coastal areas and inland salinity due to canal irrigation give rise to poor quality of ground water in the country. Exploitation of ground water in the country is increasing day by day which may create ground water crisis in the year to come. Large number of centre and state level organisation have been set up to investigate the ground water potential and quality at state, district and block level to meet the local demand.The state Odisha is located along the eastern coast of India (Latitude 17 49′ to 22 34′ N and longitude 81 24′ to 87 29’E) occupies an area of 1,55,707 sq.
km. The Bay of Bengal forms the eastern boundary, stretching over a distance of 450 km. The state presents varied and picturesque landforms.
The hilly and mountain terrain in southern Odisha change to the rolling uplands and plateaus on the west and north and descend onto the valleys and floodplains of the major river system draining in the state. The plains merge with the narrow coastal tract bordering the Bay of Bengal. The plateaus form a lat upland terrain covering parts of north, northwest, southwest of Odisha. The general elevation ranges from 500m to 600m above mean sea level (MSL). The chain of hills in the mountainous southern Odisha forms parts of the Eastern Ghats extending over a distance of about 250kms. The rolling uplands have a moderate height between 150m and cover parts of central, western and southern Odisha. The rivers Mahanadi, Baitarani, Brahmani, Rushikulya, Vanshadhara and Tel drain the river valleys and plains. The coastal plains forms an extensive alluvial tract stretching from the Subarnarekha river in the north to Rushikulya river in the south.
Odisha is one of the economically backward states in the country. Although endowed with vast ground water resources, this stage is lagging behind most other states in harnessing its ground water wealth. The stage of the ground water development is hardly 8%of the total usable resources. The varied hydro-geochemical and hydro-meteorological factors of the state have led to wide variation in ground water regime. The variation in ground water is also due to varied geomorphic and geologic set up, which control the occurrence and yield potential of ground water reservoir. The ground water development strategies vary in hilly terrain depending upon the availability of exploitable ground water resources, cropping pattern and irrigation needs. In the hard rock terrain which covers about 8% of the state, ground water potential is limited to moderate and weathered residium and fractured rock below.
The thick sedimentary pile in the coastal tract contain extensive aquifer zones with vast development possibilities, despite constraints of ground water resources requires an in-depth understanding of the aquifer distribution under varied hydro-geomorphic and hydrogeology condition of the stateThe geological setting of the state shows a three-fold classification of hydro-geological condition depending on the lithologic framework. The coastal alluvium extending from Balasore to Ganjam district forms unconsolidated formation composed of sand, gravel, silt, clay and laterite. It has extensive confined and unconfined aquifers down to 150m to 300m. Here the ground water potential ranges from 15 lit/sec to 40 lit/sec or more. It is also marked by saline water incursions.
The Mahanadi graben extending in a NW-SE direction from Sambalpur to Dhankanal for a stetch of about 200kms of Gondwana sediments composed of conglomerate, sandstone, grit, shale, coal, etc. has a discontinuos confined to unconfined aquifer with a low yield of ground water potential estimated to be less than 15 lit/sec. The unconsolidated formation of Archean to Proterozoic occurring in the western and northern Odisha are represented by Eastern Ghat Group, Iron ore Group, Gangpur Group and Chhatishgarh Group. These are composed of hard rocks e.
g. granite, gneiss, khondalite, charnockite, slate, phyllite, schist, marble, quartzite, shale, orthoquartzite, banded hematite quartzite(BHQ), banded hematite jasper(BHJ), volcanic, limestone and dolomite copying 80% of the state where groundwater is restricted to weathered residium and fractured zone. The yield of groundwater in this area is 15 lit/sec to even less than 1 lit/sec. Bhadrak( north latitude 200 45′ & 210 14′ and east longitude 860 17′ & 860 59′) is a city and municipality in Bhadrak district in the state of Odisha, India. In the recent years there has been significant rise in local and floating population in the area, which has hiked the demand for drinking water and ground water resources. However, as the area lies in coastal alluvium like saline soil, alluvial soil and sandy soil, groundwater resource is not distributed ubiquitously.
Moreover the potential is not same everywhere. Groundwater quality is also not upto standard in all places.The ground water survey of the area has been undertaken by central and state government agencies like Central Ground Water Board (C.
G.W.B.), Rural Water Supply and Sanitation (R.W.S.
S.), and Ground Water Survey and Irrigation (G.W.S.I.) dept.
of Govt. of Odisha. But there area of operation is limited only to few urban areas.
Thus, a comprehensive study on groundwater quality of the area is lacking.In this view of this, an attempt has been made in the present study to access the groundwater quality of the area for a balanced development and utilization of the groundwater resources of the area. ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? CHAPTER-2 AREA UNDER STUDY ?CHAPTER-2AREA UNDER STUDY2.1 LOCATION The area under study forms a part of Bhadrak district of Odisha.
The area falls in the survey of India Toposheet No. F4508 and F45012 and is bounded by latitudes 210 to 2107’30” and longitudes 86022’30” to 86035′.2.
2 ACCESSIBILITYThe area has a good network of road connectivity. The National High Way No.5 and S.E Railway line connecting Kolkata and Chennai passes through the Bhadrak district.
The city is the main district headquarter of Bhadrak and well connected to its village area by concrete roads some of which are made under Pradhan Mantri Gramya Sadak Yojana. The distance of Bhadrak town from Bhubaneswar is nearly 125 km. 2.3 PHYSIOGRAPHY AND DRAINAGE The area is bounded by latitudes 210 to 2107’30” and longitudes 86022’30” to 86035′.
It falls in the Bhadrak district of Odisha. The topography is mostly rolling with an average elevation of 23 m (75 ft) above mean sea level (MSL). The general slope is towards east and south-east which varies from 5 to 1.
1 metre per kilometre from north-west to south-east.The district forms the outfall area of the Baitarani River along with its tributaries form the drainage system of the area and flows along the Southern boundary of the district. Salandi and Kapali are the main tributaries of the Baitarani River which flows through the study area and have developed extensive flood plains comprising unconsolidated materials. The flood plains are occupied by residential area and many with cultivated land. The area experience warm to hot climate with temperature rising above 400C during summer months.
The Salandi River which is the main tributary of the Baitarani River flows from north-west to south-east direction of the study area. Most of the drainage pattern is dendritic. The river is the main source of drinking water and irrigation. The ground water recharge in the Bhadrak city is entirely dependent on the Salandi River. 2.4 CLIMATE AND RAINFALL The study area is characterized by tropical monsoon climate having three distinct seasons in the year, viz. winter, summer and rainy seasons.
The Bay of Bengal, which forms the eastern boundary of the district, plays a prominent role in controlling the climate of the district. The winter commences from late November and continues till end of February. The winter followed by the summer season, which extends upto mid June. During the period between April and May, 3 to 4 cyclonic storms accompanied with rains generally occur in the area. The rainy season sets-in at the advent of the southwest monsoon, generally from the middle of June and continues till end of September.The average lowest and the highest temperatures for the district are 170C and 480C respectively. The average annual temperature of the study area is 26.80C.
The normal annual rainfall is 1427.9 mm (1994 – 2009). During the 2015, the annual rainfall was recorded as1616.7 mm.The relative humidity, on an average, varies from 40 to 90% during the year and during monsoon it is much more.
The mean monthly potential evapotranspiration varies from 4.51 cm during January to 27.68 cm during May. BHADRAK TOWN MAP 2.
5 GEOLOGYThe geological formations, which are exposed in the area belongs to quaternary period and these are recent alluvial sand dunes, older alluvium, laterites and lateritic gravels. The exploratory drilling of CGWB has revealed the existence of Precambrian crystallites Stratigraphy :- The generalised geological succession of the study area is given in table.Table No.2.1 Stratigraphy of the study area Period Epoch Formation DepthCenozoic Quaternary Recent to Pleistocene Recent alluvia, sand dunes, older alluvia, lateritic gravel, sand stone etc. 29m to 601m Tertiary Mio-pliocene Brown, yellows and grey sand, gravels and clays, gritty sand stone ,shale etc. Miocene Grey clays , sand, mollascan shells, shelly limestone, shale etc.
72m to 330m Unconformity Precambrian Granite gneiss 173m to 402mThe Precambrian granite gneiss encountered in the boreholes, at depths ranging from 173m to 402m below grounds level. The tertiary sediments encountered in the bore holes comprise marine fossiliferous sequence of Miocene overlain by an estuarine sequence of mio-pliocene time. The fossiliferous marine formation encountered at different depth ranging from 72 to 330m below ground level. The younger unfossiliferrous estuarine sediments are encountered from 29m to 601m depths, in different bore holes and this may extend beyond 601m depth.The alluvium is the youngest geologic unit of late Pliestocene to recent age. It consists of sand, silt, clays and gravels.
It is mainly developed in the valleys of the river channels. ? CHAPTER-3METHODS OF INVESTIGATIONCHAPTER-3METHODS OF INVESTIGATION3.1 COLLECTION OF GEOLOGICAL AND HYDROLOGICAL DATAThe very first step of geological research is to get a Toposheet in which the study area lies. The present study areas lies in Toposheet No. F4508 and F45012 of survey of India. The geology of the area has been described in the previous chapter. To study the hydro-geochemistry of the study area post monsoon period was chosen. Monsoon is an important factor in the hydro-geochemistry of an area, because it dilutes the actual chemical concentration of water.
3.2 FIELD SAMPLING 25 No. of samples were collected from the area in the pre monsoon period, in the month of April 2017. The location of samples is presented in the Table No.3.1.
The samples were collected from 25 tube-wells, taking into account the every precautionary measure.• Air tight rectified clean polythene bottles of 500ml capacity were used during sampling to preserve sample from oxidation on exposure to atmosphere.• The bottles were first rinsed thoroughly with the water to be sampled, filled with sample and then closed tightly and numbered properly.The location of collected water samples is as follows: Table No. 3.1 Sl. No. Sample No.
Type of wells Location 1 T1 Tube well Brahmapur 2 T2 Tube well Ramakrushnapur 3 T3 Tube well Saratola 4 T4 Tube well FACOR 5 T5 Tube well Randia 6 T6 Tube well Kaupur 7 T7 Tube well Baghurai 8 T8 Tube well Baudpur 9 T9 Tube well Gelpur 10 T10 Tube well Naripur 11 T11 Tube well Asthal 12 T12 Tube well Jagannathpur 13 T13 Tube well Sahapur 14 T14 Tube well Matha Sahi 15 T15 Tube well Kacheribazar 16 T16 Tube well Shankarapur 17 T17 Tube well Purunabazar 18 T18 Tube well Mauda 19 T19 Tube well Belada 20 T20 Tube well Bhadrakali 21 T21 Tube well Balipatna 22 T22 Tube well Charampa 23 T23 Tube well Ichhapur 24 T24 Tube well Naya Bazar 25 T25 Tube well Koda,Gambhira3.3. LABORATORY ANALYSIS:In the laboratory the samples were passed through two types of analysis.• Physical analysis: It was introduced to measure the physical parameters of the samples like pH, EC, TDS.
• Chemical analysis: This analysis was done to detect and measure the chemical parameters which are Total alkalinity (TA), Total Hardness (TH), Ca, Mg, Na, K, Cl, CO3, HCO3, SO4.3.3.1 PHYSICAL ANALYSIS: Hydrogen ion concentration (pH) pH of water sample were determined by systronics makes digital pH meter 335.
The instrument was first standardized by buffer solution of pH value 7.0 and 4.0 by proper adjustment. After the standardization the samples were analysed with the help of pH electrode and values were recorded.Electrical conductance (EC) The EC was determined by a condensed operating instrument that is the water analysis, 371eletrochemical analyser. Instrument was standardized by three KCl solutions (0.1N, 0.01N, 0.
001N) with proper adjustment. The electrode cell having cell constant 1+10% was chosen for the analysis of the samples and specific values were observed on the digital window.TDS (Total Dissolved Solids) TDS values were obtained by multiplying EC values with a factor of 0.64.3.3.
2 CHEMICAL ANALYSIS:Phenolphthalein alkalinity (PA) & Total alkalinity (TA) Few drops of phenolphthalein indicator were added to fixed volume of sample. If the solution remain colourless, PA=0 and total alkalinity is determined by titrating this solution with fixed normality of HCl. If the colour changed to pink after addition of phenolphthalein, the solution was titrated with a fixed normality of HCl until the colour disappeared and PA was calculated usig the following formula. Then 2-3 drops of methyl orange was added to same solution and titration was continued until the yellow colour changed to pink and TA was calculated as per the formula given below.PA = A x normality of HCl x1000 x 50 ml. of sample taken ? A= ml. of titrant usedT.A.
= B x normality of HCl x1000 x 50 ml. of sample taken? B= ml. of titrant usedTotal Hardness (TH) The indicators and essential chemicals are:? EDTA (Ethylene Diamene Tetra-Acetic Acid)? EBT (Erichrome Black T)? Ammonia Buffer Solution A pinch of indicator powder and few drops of ammonia buffer solution were mixed with a fixed volume of water sample and then titrated with fixed normality of EDTA.Formula for TH calculation: TH = B x normality of EDTA x 1000 x 50 ml. of sample taken? B = volume of EDTA consumed.MAJOR CATIONSCalcium (Ca):The indicator and essential chemicals are:? EDTA? NaOH Solution? Murexide indicator A fixed volume of NaOH solution and Murexide indicator was mixed with the water sample which gives pink colour. It was titrated with a fixed normality of EDTA till purple colour occurred.
Calculation for calcium: Ca = B x normality of EDTA x 1000 x 40.8 ml. of sample taken• B = volume of EDTA consumed.Magnesium (Mg): Mg was determined by the help of TH value by applying following formula: Mg = TH – 2.5 x Ca 4.1or TH = (2.
5 x Ca) + (4.1 x Mg)Sodium and Potassium (Na & K): These cations are estimated by systronics make flame photometer 128.• For Na, instrument was standardized with five standard solutions of NaCl of different concentrations. Then water samples were analysed and results were observed on the digital window.
• Similarly for K, numbers of KCl solutions of different concentrations were used to standardize the instrument and results were observed on the digital window.MAJOR ANIONSChloride:The indicators and essential chemicals are • Silver Nitrate• Potassium chromate indicator K2CrO4 was added to the water sample which gave yellow colour and titrated with AgNO3 till brownish red colour occurred. Cl in mg/l = V x normality of AgNO3 x 1000 x 35.5 ml. of sample taken• V = volume of AgNO3 used.Bicarbonate: For the estimated of bicarbonate in mg/l the following values of the same sample were taken into account.
• Phenolphthalein alkalinity (PA)• Total alkalinity (TA)• Total dissolved solids (TDS)The estimation was done by means of the following formulae:-1. In case of TDS 500 ppm :Bicarbonate was calculated from Phenolphthalein alkalinity (PA) and Total alkalinity (TA) as follows: Alkalinity result Bicarbonate in mg/l CaCO3 P = 0 T P 1/2T 0 P = T 0 Table No. 3.2 Carbonate: The same values were taken into account as in case of bicarbonate estimation and also there were two formulae involved.1.
In case of TDS 500 ppm: Carbonate calculated from Phenolphthalein alkalinity (PA) and Total alkalinity (TA) as follows: Table No. 3.3 Alkalinity result Carbonate in mg/l (CaCO3) P = 0 0 P ½ T 2(T – P) P = T 0Sulphate:The chemicals used in the estimation of sulphate are:• Conditioning reagent comprising of NaCl, HCl (conc.), Isopropyl alcohol, Glycerol, Distilled water.
• Standard sulphate solution • BaCl2 crystals. Fixed volume (10 ml) of water sample was mixed with 1 ml of conditioning reagent and stirred with a magnetic stirrer. During stirring, a pinch of BaCl2 crystals were added and stirring was done for another one minute. The sulphate ions present in the water sample precipitated as BaSO4 and turn the solution turbid. The turbidity thus produced was compared with that of standard sulphate solution undergoing the same process, by a spectrophotometer at 420 nm, exactly after 4 minutes and the concentration of sulphate in the water sample was measured. For accuracy in measurement, the water sample was diluted to different degrees and compared with a set of standards.
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? CHAPTER – 4HYDROGEOCHEMISTRYCHAPTER – 4HYDROGEOCHEMISTRY4.1 INTRODUCTIONWater is essential for all forms of life on earth. At present due to rapid economic development and man’s interference on environment, a large number of sources and causes modify surface water as well as ground water quality.
In comparison to surface water pollution, subsurface water pollution is difficult to detect and control. Since it is a fundamental requisite and its quality differs place to place, it should be ascertained before its use.Ground water quality can be represented by physical, chemical and biological properties. The physical ties are like PH, TDS, EC, etc. Chemical properties include major cations, total hardness, total alkalinity etc. Biological properties include bacterial effects on study area are described.4.2 EVALUATION OF PHYSICAL PROPERTIES Hydrogen ion concentration (pH)pH is known as negative logarithm of hydrogen ion concentration in moles per litre.
The pH value of neutral water is 7. If the value is less than 7 then it is considered as acidic nature and if more than 7 then it’s considered as alkaline nature. Most of the natural water have pH value varying from 6.5 to 8.
0 and having pH value less than 5.5 is rarely found. Water with high carbonate content has high value of pH like water having pH value 8.
5 or more are normally associated with sodium carbonate and bicarbonate. pH of the water samples of the study area varies from 6.14 to 8.58. Variation of pH of collected water samples from Bhadrak area: Sample No. Total dissolved solids (TDS) The total dissolved solids indicate the dissolved salt concentration present in the water. It indicates bicarbonate, sulphates and chlorides of calcium, magnesium, sodium and silica.
Potassium, chloride, nitrate and boron form a minor part of the dissolved solids in ground water. Heavy metals and radioactive constituents occur in trace quantities. TDS is related to EC , can be determined by multiplying EC with the factor 0.64( Garg, 1982).
TDS of the water samples of the study area varies from 266 to 832 mg/l. Electrical conductance (EC): Electrical conductance is the ability of water to conduct electric current. It is defined as the conductance of a cubic centimeter of water at a standard temperature of 250 C. Conductance is measured in micro mho/cm or mili mho/cm units.
For the drinking purpose no limit of electrical conductance is given but suitability of water for irrigation purposes can be determined. Presence of dissolved ions makes the water conductive. So it is a function of temperature, type of ions present and their concentration. Specific conductance of the water samples of the study area varies from 417 to 1300 micro mho/cm.Variation of TDS of collected water samples from Bhadrak Area: Table No.
4.1 Physical parameters of the ground water samples from the study areaSample number pH E.C in (micromho/cm) TDS in (mg/l) T1 8.03 671 429.44 T2 7.9 551 352.64 T3 8.36 651 416.
64 T4 7.84 432 276.48 T5 6.
83 1160 742.4 T6 8.36 895 572.8 T7 8.08 828 529.
92 T8 7.9 641 410.24 T9 8.03 1180 755.2 T10 8.22 913 584.
32 T11 7.95 865 553.6 T12 8.
3 1010 646.4 T13 7.72 996 637.44 T14 8.
05 590 377.6 T15 6.14 752 481.28 T16 7.23 754 482.
56 T17 7.24 1300 832 T18 7.91 767 490.88 T19 8.58 648 414.72 T20 8.49 504 322.56 T21 6.
47 417 266.88 T22 6.67 757 484.48 T23 7.34 520 332 T24 8.1 925 592 T25 8.49 525 336?4.3 EVALUATION OF CHEMICAL PARAMETERSTotal alkalinity (TA): The total alkalinity is the measure of the capacity of water to neutralize a strong acid.
The alkalinity of water is due to presence of carbonate, bicarbonate and hydroxyl ion in free states. In normal ground water total alkalinity is less than 10mg/l, however presence of sodium can increase the concentration up to 250 mg/l. The collected water samples from the study area have a total alkalinity value varies from 130 to 300 mg/l.Total hardness (TH): Total hardness denotes the concentration of calcium and magnesium in water, and is expressed as the equivalent of CaCO3. It is present in ground water due to its contact with minerals such as compounds of Mg, Fe, Sr, Ca and free acids. The hardness prevents soap lathering and increases its boiling point. It is generally classified in to hard and soft water. Hard water is unsuitable for the house hold cleaning purpose because of adverse action with soap.
Total hardness is expressed as:TH=Ca x ( CaCO3 / Ca )+Mg x ( CaCO3 / Mg )Total hardness of water samples of the study area varies from 90 to 510 mg/l.Table NO. 4.2: Chemical parameters of the samples from the study area Sample No. Total Alkalinity in mg/l Total Hardness in mg/l T1 260 230 T2 230 200 T3 260 270 T4 240 140 T5 130 270 T6 230 280 T7 240 280 T8 240 200 T9 230 350 T10 250 310 T11 180 220 T12 280 340 T13 250 300 T14 240 220 T15 220 190 T16 200 260 T17 260 510 T18 250 230 T19 300 170 T20 220 90 T21 120 110 T22 280 290 T23 180 160 T24 190 260 T25 230 190COMMON CATIONSCalcium (Ca2+): Calcium is one of the principal elements in most of the natural ground water because it is a major constituent of most igneous, metamorphic and sedimentary rock. The principal sources of calcium in ground water are silicate group of minerals like plagioclase, pyroxene and amphibole in igneous rocks and limestone, dolomite and gypsum in sedimentary rocks. Weathering of silicate minerals in presence of carbon dioxide release calcium in to ground water. Calcium has got a high affinity to absorb soil particles.
In the samples collected from the study area calcium content varies from 28 to 120 mg/l.Magnesium ( Mg2+): Like calcium generally occurs along with calcium in ground water, but its concentration is relatively low. The source of magnesium in ground water is dolomite in sedimentary rocks, diopside and tremolite in metamorphic rocks.
The decomposition of ferromagnesian mineral may contribute magnesium to ground water. Its content in ground water is controlled by the presence of carbon dioxide. The magnesium content in the samples collected from the study area varies from 4.88 to 51.22 mg/l.Sodium (Na+): Among the alkalis, sodium is one of the important chemical parameter of ground water.
Weathering product of albite, plagioclase feldspar, nepheline, etc. are responsible for increase in sodium in ground water. Most of the sodium salts are readily soluble in water, but take no part in chemical reaction as do the salts of alkaline earth.
Sodium content in water ranges from 1 ppm in humid and snow fed regions to over 100,000 ppm in brines. Sodium is very important to determine the quality of irrigation water. In the collected samples from the study area sodium content varies from 15.
52 to 75.89 mg/l.Potassium (K+): Potassium is less abundant in ground water than sodium and being more soluble than sodium salts, it is last to crystallize in evaporation.
The common sources of potassium are orthoclase, microcline, nepheline, leucite and biotite in igneous and metamorphic rocks and evaporites containing sylvite and niter in sedimentary rocks. The concentration of potassium ranges from 1 ppm or less to about 10 to 15 ppm in portable water and from 100 ppm to over several thousand ppm in brines. In the collected samples from study area potassium content varies from 0.29 to 11.87 mg/l.
Table No. 4.3 Values of major cations of the samples of the study area in (mg/l) Sample Number Calcium (Ca2+) Magnesium (Mg2+) Sodium (Na+) Potassium (K+) T1 44 29.
27 18.86 0.47 T2 56 14.63 20.62 0.49 T3 84 14.
63 16.92 0.29 T4 32 14.63 48.97 1.74 T5 64 26.
83 74.11 11.87 T6 56 34.14 26.
91 0.40 T7 68 26.83 21.58 1.50 T8 52 17.07 19.27 1.
94 T9 76 39.02 37.05 11.87 T10 84 24.
39 27.91 0.96 T11 60 17.07 25.79 3.33 T12 84 31.71 38.64 2.
83 T13 88 19.51 28.63 2.35 T14 60 17.07 19.21 0.65 T15 56 12.19 36.
26 0.93 T16 60 26.83 21.13 3.06 T17 120 51.22 75.89 4.16 T18 56 21.
95 27.05 3.92 T19 40 17.
07 49.83 1.77 T20 44 4.
88 20.35 3.81 T21 28 9.756 15.52 0.61 T22 68 29.
27 29.10 1.41 T23 44 12.19 18.26 0.49 T24 56 29.27 18.
81 0.55 T25 52 14.63 12.89 0.56 COMMON ANIONSChloride (Cl- ): Chloride is an important anion present in ground water, chlorine, the member of halogen group is generally present as dissociated chloride (Cl-) ions.
The chloride content in the rain water is generally less than 10 ppm but it can be high in coastal and desert areas. Discharge of sewage waste, salting of certain types of trees such as coconut leaching of saline residue in soil are the main source of chloride in ground water. Chloride bearing rock mineral like sodalite and chloroapatite are minor source of chloride in ground water. Halite and evaporite of sedimentary rocks give rise to high concentration of chloride in ground water. In the collected samples of Bhadrak town area, the chloride content varies from 40 to 250 mg/l. Carbonate and bicarbonate (CO3-2 and HCO3- ): The carbonate and bicarbonate content in ground water is due to presence of dissolved carbon dioxide in snow and rain water. Rain water coming in contact with the atmospheric gases like carbon dioxide, carbon dioxide gets dissolved in it and is converted into carbonate and bicarbonate.
The rain water containing carbonate and bicarbonate percolates through the soil horizon into the ground water regime. High concentration of sodium is responsible for high concentration of carbonate in natural water (Garg 1982). Carbonate in water does not have adverse impact on health but it may create imbalance in the ecosystem. The carbonate content is ordinarily less than 10 ppm. The bicarbonate content of ground water sample of the study area varies from 6.73 to 280 mg/l.
Sulphate (SO4-2): Like Ca, Na, and Mg, sulphate may be present in higher concentration in ground water because of its high solubility. Sulphate content in ground water is due to oxidation, precipition and solution. When water moves through rocks having sulphate minerals, sulphate is introduced in to ground water. Sulphides of heavy metals, sulphur minerals in igneous and metamorphic rocks and gypsum and anhydrite in sedimentary rocks are the main source of sulphate in ground water. Application of sulphatic fertilizer in the agricultural fields also adds sulphate to ground water. Sulphate varies from 36.
5 to 55.3 mg/l in the water samples of the study area. Table No.4.4 Values of major anions of the water samples from the study area in mg/l. Sample No. Chloride (Cl-) Sulphate (SO4-2) Carbonate (CO3-2) Bicarbonate (HCO3-) T1 65 51.6 189.
8 20.19 T2 50 53.7 162.68 17.31 T3 95 47.8 189.8 20.19 T4 40 53.
4 171.73 18.27 T5 147.5 47.7 0 130 T6 140 55.3 0 230 T7 110 47 0 240 T8 85 53.8 325.
38 34.61 T9 250 43.7 0 230 T10 110 36.8 0 250 T11 120 36.6 0 180 T12 145 36.5 0 280 T13 185 37.1 0 250 T14 60 51 171.
73 18.27 T15 125 39.6 153.65 16.34 T16 140 47.8 135.57 14.42 T17 310 40.
8 0 260 T18 100 43.4 397.68 42.30 T19 55 53.9 225.
95 24.04 T20 75 50.3 153.
65 16.34 T21 120 47.3 63.26 6.
73 T22 115 39.2 207.88 22.
11 T23 80 50.5 117.5 12.5 T24 125 45.9 0 190 T25 42.5 54.7 162.68 17.
30HYDROCHEMICAL FACIES:The hydrochemical facies concept was proposed by Back (1962) and Seaber (1962), which is represented by arranging the ionic percentage in decreasing order. It gives an idea about chemical composition of ground water. It was found that Ca2+ is dominant among cations and Cl is dominant among anions in the water samples of the study area. Table No.
4.5 Hydrochemical facies of ground water of the study area. Sample Number Cation facies Anion facies T1 Ca > Mg >Na > K Cl > SO4 > HCO3 T2 Ca > Na >Mg > K SO4 > Cl > HCO3 T3 Ca > Na > Mg > K Cl > SO4 > HCO3 T4 Na > Ca > Mg > K SO4 > Cl > HCO3 T5 Na > Ca > Mg > K Cl > HCO3 > SO4 T6 Ca > Mg > Na > K HCO3 > Cl > SO4 T7 Ca > Mg > Na > K HCO3 > Cl > SO4 T8 Ca > Na > Mg > K Cl > SO4 > HCO3 T9 Ca > Mg > Na > K Cl > HCO3 > SO4 T10 Ca > Na > Mg > K HCO3 > Cl > SO4 T11 Ca > Na > Mg > K HCO3 > Cl > SO4 T12 Ca > Na > Mg > K HCO3 > Cl > SO4 T13 Ca > Na > Mg > K HCO3 > Cl > SO4 T14 Ca > Na > Mg > K Cl > SO4 > HCO3 T15 Ca > Na > Mg > K Cl > SO4 > HCO3 T16 Ca > Mg > Na > K Cl > SO4 > HCO3 T17 Ca > Na > Mg > K Cl > HCO3 > SO4 T18 Ca > Na > Mg > K Cl > SO4 > HCO3 T19 Na > Ca > Mg > K Cl > SO4 > HCO3 T20 Ca > Na > Mg > K Cl > SO4 > HCO3 T21 Ca > Na > Mg > K Cl > SO4 > HCO3 T22 Ca > Mg > Na > K Cl > SO4 > HCO3 T23 Ca > Na > Mg > K Cl > SO4 > HCO3 T24 Ca > Mg > Na > K HCO3 > Cl > SO4 T25 Ca > Mg > Na > K SO4 > Cl > HCO34.4 HYDROGEOCHEMICAL CLASSIFICATIONBased on TDS value:TDS values is a convenient way to know the quality of water whether it is saline or non-saline. The U.S Geological survey has classified the water based on TDS value which is given below. In the study area TDS value of water samples varies from 266 to 832 mg/l. Table No. 4.6 Type TDS in mg/l No. of samples out of 25 Non-saline 35,000 0Based on hardness:Twortetal (1974) classified water according to hardness as shown below:-Table No. 4.7Hardness in mg/l as CaCO3 Quality of water No. of samples out of 25 0-75 Soft 0 75-150 Moderately hard 3 150-300 Hard 18 >300 Very Hard 4Total hardness is the concentration of calcium and magnesium in water and it is expressed as the equivalent of CaCO3. Total hardness of the study area ranges from 90 to 510 mg/l and these hardness values are classified in the above table.Based on Sodium Adsorption Ratio (SAR)Sodium adsorption ratio is one of the criteria to study the suitability of water for irrigation. According to laboratories of United States Department of Agriculture (USDA), SAR has direct relation to the adsorption of sodium by soil and hence needs to be assessed.SAR is calculated as per the following formula:-SAR = Na+ / {( Ca+2 + Mg+2 )/2}1/2Here the concentrations are expressed in epm. On the basis of SAR value, the suitability of ground water for irrigation purpose is determined as per the following table.Table No. 4.8Water class for irrigation SAR value in epm No. of samples out of 25 Excellent Upto 10 25 Good 10 to 18 0 Medium 18 to 26 0 Bad >26 0 The SAR value of the ground water samples varies from 0.45 to 1.93. All the samples come under excellent category for irrigation.Based on Kelly’s Ratio (KR): Kelly (1963) defined the Kelly’s Ratio as: KR = Na / (Ca + Mg) Here the concentrations are expressed in epm. The water quality is good for irrigation, when Kelly’s Ratio is less than 1. The KR values of the collected samples vary from 0.14 to 0.79. All the samples are good for irrigation purpose.Based on Magnesium Adsorption Ratio (MAR):Magnesium Adsorption Ratio is defined as:- MAR = (Mg x 100) / (Ca + Mg) Here all the values are in epm. Due to excess Magnesium, crops yield may be poor resulting in deterioration of soil quality. The MAR values of the samples vary from 15.10 to 57.07.Based on Permeability Index (PI): Doneen (1964) proposed permeability index for classification of ground water for irrigation. Permeability is expressed as PI = (Na + HCO3)1/2 x 100 / (Ca + Mg + Na) Here all the concentrations are expressed in epm. The PI value of the water samples of the study area varies from 17.88 to 35.07.Based on Potential Soil Salinity (PS):Potential soil salinity is calculated by using the following formula. PS = Cl + 1/2SO4All the values are in epm. The PS values of the study area vary from 1.33 to 6.6 and the samples can be classified in the following classesTable No. 4.9Potential Soil Salinity Class No. of samples out of 25 10 Injurious to unsatisfactory 0 Based on Residual Sodium Carbonate (RSC):Residual sodium carbonate is determined by applying the formula RSC = (CO3-2 + HCO3-) – (Ca+2 + Mg+2)All the values are in epm. The relative abundance of sodium with respect to excess of carbonate and bicarbonate over alkaline earth affects the suitability of water for irrigation purpose. With respect to RSC values, the ground water can be classified into following types.Table No. 4.10Residual Sodium Carbonate Class No. of samples out of 25 2.25 Bad 6Most of the ground water samples have RSC values less than 2.25. They are classified under “good to bad” category.Based on Percent Sodium:Wilcox (1948) defined the percent sodium as:%Na = {(Na + K) / (Na + K + Ca + Mg)} x 100Here all the values are in epm.The different classes for irrigation on the basis of %Na is as follows:Table No. 4.11Water class for irrigation %Na No. of samples out of 25Excellent Upto 20 14Good 20 – 40 8Permissible 40 – 60 3Doubtful 60 – 80 0Unsuitable ;80 0From the above table all the samples from the study area are excellent to permissible category for irrigation purpose.Based on pH:pH value is an important parameter for ground water used in drinking purposes. The water may be classified as strongly acidic, acidic, neutral, alkaline and strongly alkaline.Table No. 4.12 Class of water pH values No. of samples out of 25 Strongly acidic
